This specification relates to information presentation.
Sponsored content (e.g. advertisements, deals or special offers) can be provided over the Internet to various user devices. For example, a web page can include slots in which sponsored content can be presented. These slots can be defined in the web page or defined for presentation with a web page, for example, along with search results or other content. Sponsored content can also be delivered through dedicated web portals or applications executing on the user devices.
Some content items are expandable. For example, a content item can be initially presented in an unexpanded form as a 728×90 pixel graphical item. When a user selects or interacts with this content item, an expanded view of 728×270 pixels can be presented. To facilitate the processing of expandable content items in particular types of content item slots, such as iFrames, a content item provider (such as, in the case of advertisements, an advertiser or a vendor that handles the placement of advertisements for advertisers) provides a “publisher side file” (PSF) for a publisher host. The PSF file stores instructions that are used to ensure proper rendering, expansion and contraction of the expandable content item. Often the content item provider specifies location on the publisher host for storing the file so that a user device can request the publisher side file from the host. For example, a specified location for a particular vendor Vendor1 may specify a directory entitled “Vendor1Path” at the root of a publisher webserver. Thus, the PSF file V1PSF.html for Vendor1 for a host www.example1.com may be retrieved by the URL:
http://www.example1.com/Vendor1Path/V1PSF.html.